Process for bringing together, aligning, and co-processing flaccid workpiece layers

ABSTRACT

A process and device for automatically feeding workpiece layers to be processed in a hanging position in a vertical plane to a scanning and aligning station (R). The workpiece layers are grasped individually in a horizontal starting position, brought into the vertical position, and transferred to the scanning and aligning station (R), from which they are taken over directly after alignment and forwarded to the processing station (N). The device for carrying out this process has two conveyors (F and F&#39;), each of which consists of a feed conveyor (Z; Z&#39;) designed as a manipulator and a transport mechanism (T; T&#39;) formed by a conveyor belt (48; 48&#39;). The workpiece layers are held by controllably movable clamps (20; 20&#39;) in the scanning and aligning station (R). The transport mechanisms (T and T&#39;) can be moved to and fro between a carrying position and a non-carrying position in the area of the clamps (20 and 20&#39;). As a result of which the feed conveyors (Z and Z&#39;) are able to transfer the workpiece layers to the clamps (20 and 20&#39; ), and these the clamps are able to move freely for mutually aligning the workpiece layers.

FIELD OF THE INVENTION

The present invention relates in general to a process and device forbringing together, aligning and co-processing flaccid workpiece layersand specifically to moving layers of fabric from a horizontal positionto a vertical position where two layers of fabric to be joined arealigned with each other and then transferred to a processing site wherean edge of the two fabrics can be sewn together.

BACKGROUND OF THE INVENTION

A similar process and device are described in European Patent DisclosureDocument No. EP-OS 0,260,331.

In the prior-art process, the workpiece layers are fed toward each otherby means of conveying means. The conveying means comprise rail-guidedcarriages on which clamps are arranged that hold the upper end of theworkpiece layers. These conveying means have track sections directed inparallel to one another in a scanning station and an aligning station.To make possible the mutual alignment of the workpiece layers, theclamps on the carriages of one of the conveying means are arranged bymeans of a holding head that is movable in a plurality of directions inrelation to the carriage carrying it. This holding head carries amagnetizable plate that comes into frictionally engaged contact, in thealigning station, with a permanent magnet that is fastened to theadjacent carriage of the other conveying means. Using an adjustingdevice of the stationary aligning station, the movable holding head ofthe clamps on the first-named carriage is adjusted corresponding to thescanning result so that the two workpiece layers that are locatedadjacent to one another in the aligning station will reach thepredetermined relative position. Due to the frictional engagementbetween the magnetizable plate on the holding head of one carriage andthe permanent magnet on the other carriage, this relative position willbe maintained when the two carriages move together from the aligningstation into a subsequent processing station after alignment of theworkpiece layers.

This design is relatively complicated, because it requires a holdinghead that is adjustable in a plurality of directions on each of thecarriages of one conveying means. In addition, to adjusting the holdingheads, the adjusting device must apply a considerable force to producethe specified relative position of the two workpiece layers in order toovercome the frictional force between the magnetizable plate and thepermanent magnet, which must, as is explained, be strong enough tomaintain the relative position, once set, between the permanent magnetand plate and consequently the aligned position of the workpiece layers.

It is assumed in the prior-art process that the workpiece layers to bebrought together are already suspended on the clamps carried by thecarriages of the conveying means, and the manner in which thissuspension was performed is left open.

SUMMARY AND OBJECTS OF THE PRESENT INVENTION

The basic task of the present invention is to provide a process whichmakes it possible to automatically feed the workpiece layers to thescanning and aligning station, on the one hand, and is designed, on theother hand, such that this can be carried out with a device of simpledesign.

The task of the present invention is accomplished by having first andsecond workpieces lying substantially horizontal on a support table. Thefirst and second workpieces lie side by side and these first and secondworkpieces are to be joined together, preferably at an edge. The firstand second workpieces are grasped from this horizontal support table andmoved to a scanning and aligning station. As the first and secondworkpieces are moved to the scanning and aligning station, they areturned so that the workpieces are substantially vertical and positionedsubstantially flat opposite each other. The workpieces are positioned atopposite sides of an intermediate plate and are held against thisintermediate plate by first and second clamping means, respectively. Atleast one of the clamping means is movable in order to align at least anedge of one of the workpieces with the edge of the other workpiece. Ascanning means operates in cooperation with a clamp movement means inorder to move the clamp and therefore align the first and secondworkpieces. After they have been aligned a transport means grasps thefirst and second workpieces and slides the first and second workpiecesalong the intermediate plate. The first and second workpieces are thentransported from the scanning and aligning station to a processing sitewhere the first and second workpieces are further processed, preferablyby being sewn together.

The operation where the feeding in of the workpiece layers to thescanning and aligning station is combined with the process steps ofpicking up and bringing into a vertical position makes it possibleeither to pre-align the workpiece layers to be associated with oneanother by hand on a supporting table, in which case the workpiecelayers are located next to one another and consequently do not influenceone another, or to take over the workpiece layers from an output stationof a preceding processing machine.

Since the workpiece layers are subsequently transferred to the scanningand aligning station and are then taken over for further transport inthe direction of the processing or connection site only after they havebeen aligned, the workpiece layers are separated during alignment fromthe conveying means that bring about feeding and removal, so that thealignment can take place independently and uninfluenced by theseconveying means. Based on these circumstances, it is guaranteed that thedevice for carrying out the process can be of a relatively simpledesign.

In one of the preferred embodiments of the present invention one of theedges of the first and second workpieces are aligned with each other.This edge is substantially perpendicular to a transporting direction inwhich the transport means transports the aligned workpieces to theprocessing site. The transport means stops the aligned workpieces at theprocessing site and a stitch forming machine moves along the alignededge in order to sew and connect the aligned edge.

This embodiment provides for favorable conditions for the edge-parallelconnection of two workpiece layers with highly irregular course of theedges, because the workpiece layers hang down freely from their clampingsites and are therefore able to easily perform relative movements inrelation to a stitch-forming machine moved along a straight line.

Another preferred embodiment of the present invention is where thealigned edge of the two workpieces is substantially parallel to thedirection of transport of the transport means. The transport means movesthe aligned workpieces towards and through the processing site. Duringthe transporting a stitch forming machine connects the aligned edgeswhile the workpieces are in motion.

This preferred embodiment makes it possible to process two pairs ofworkpiece layers associated with one another with an overlap in time,i.e., in a particularly efficient manner.

The device of the present invention uses first and second graspingplates to grasp the horizontal workpieces from the support table. Thesefirst and second grasping plates are pivotably connected to an arm andthe arm is pivotably connected to a frame. The arm pivots on the frameto move the workpieces from the support table to the scanning andaligning station. The arm pivots on the frame and the grasping platespivot on the arm to move the workpieces into a substantially verticalposition. Each workpiece has its own first and second grasping platesand arm. At the scanning and aligning station clamp means apply force tothe workpieces through cut outs in the grasping plates. At the scanningand aligning station the workpieces are placed against opposite sides ofan intermediate plate and first and second clamp means clamp theworkpieces against the intermediate plate. An optical scanning meanscooperates with a clamp movement means on one of the first and secondclamp means in order to align the first and second workpieces. Once thefirst and second workpieces have been aligned a transport means closesaround the first and second workpieces and slides the first and secondworkpieces by means of a conveyor belt against the intermediate plateand to the processing site. When the arm and grasping plates are movingthe workpieces to the aligning station, a first section of the transportmeans moves away from the intermediate plate in order to allow the armand grasping plates to move the workpieces to the scanning and aligningstation. Once the arms and grasping plates are removed the first sectionof the transport means can come back together to press the first andsecond workpieces against the intermediate plate for transporting thefirst and second workpieces away from the scanning and aligning stationafter they have been aligned. Deflecting wheels are positioned on theconveyor belt of the transport means in order to separate the firstsection of the transport means from the remainder of the transport meansor a second section of the transport means.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of this disclosure. For a better understanding of the invention,its operating advantages and specific objects attained by its uses,reference is made to the accompanying drawings and descriptive matter inwhich preferred embodiments of the invention are illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a synoptic graphic representation of a device with thecharacteristics of the present invention,

FIG. 2 is a sectional view from the top as a detail representation ofthe area around the sewing machine,

FIG. 3 is a detail similar to FIG. 1, in which the transfer of oneworkpiece layer to the scanning and aligning station is shown,

FIG. 4 is a front view of the scanning and aligning station with twoworkpiece layers held in it,

FIG. 5 is a sectional view of a gripper, with which one workpiece layeris removed from a supporting table,

FIG. 6 is a graphic representation of a detail from the area of thesupporting table during the transfer of one workpiece layer into thescanning and aligning station,

FIG. 7 is a partially cutaway representation of the aligning device inthe scanning and aligning station, and

FIG. 8 is a representation, similar to FIG. 1, of a second embodiment ofthe present invention for handling workpiece layers, which are fed to asewing machine along their longitudinal extension.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The device according to the present invention contains, according toFIG. 1, a plurality of cooperating basic components, namely, a frame G,two conveying means F and F' arranged next to one another, a scanningand aligning station R, as well as a sewing station N. The conveyingmeans F and F' comprise a feeding conveyor Z and Z' respectively, tofeed two workpiece layers W1 and W2 to the scanning and aligning stationR, as well as a transport mechanism T and T' respectively to forward thealigned workpiece layers W1 and W2 to the sewing station N.

The feed conveyor Z is designed as a manipulator and has an arm 1. Oneend of the arm 1 is fastened to the shaft 2 (see FIG. 3) of a gear motor3 fastened to the frame G and is pivotable around a horizontal axis. Theother end of the arm 1 is of a fork-shaped design and carries a gripper4 designed as a tong. The gripper 4 contains a first (lower, accordingto FIG. 5) grasping plate 5, which is fastened to a shaft 6 mounted atone end of the arm 1, as well as a second (upper) grasping plate 7,which is pivotably mounted on the shaft 6. A pneumatic cylinder 9, whosepiston rod 10 is hinged to a projection 11 of the second grasping plate7, is hinged to a projection 8 of the first grasping plate 5.

The shaft 6 is in driven connection with a rotary magnet 12 fastened tothe arm 1. By the rotary magnet, the grasping plates 5 and 7 are jointlypivotable around the longitudinal axis A2 of the shaft 6, and thelongitudinal axis A2 extends at right angles to the longitudinalextension of the arm 1 and in parallel to its plane of pivoting.

A plurality of flat ribs 14 extending in parallel to the plane ofpivoting of the arm 1 are provided on the underside of the firstgrasping plate 5. The two grasping plates 5 and 7 have a plurality ofopenings or cutouts 15 and 16, respectively, which extend to thedischarge-side edges of the plates, wherein the openings 15 of the firstgrasping plate 5 are aligned with the openings 16 of the second graspingplate 7. The word "discharge" describes the edge of the grasping plates5 and 7 over which the workpiece layer W1 is pulled off at the time oftransfer to the scanning and aligning station R.

The workpiece layer W1, which is to be grasped by the gripper 4, is laidon an essentially horizontally extending supporting table 17. Thesupporting table 17 may be the delivery end of an upstream processingdevice, e.g., the cooling station of a fixing machine. On the top sideof the supporting table 17, a plurality of openings 18 are provided, andthey extend substantially in parallel to the discharge-side edge of thesupporting table. The openings 18 receive the ribs 14 of the firstgrasping plate 5 when the gripper 4 is in the pickup position (FIG. 5).A corresponding beveling of the front, intake-side edge zone of thegrasping plate 5 makes it possible, when the gripper 4 is in the pickupposition (FIG. 5), at least for the beveled edge zone to be flush withthe top side of the supporting table 17 The workpiece W1 to be placed onthe supporting table 17 cannot strike and be caught by the front edge ofthe grasping plate 5. Instead the workpiece W1 will be spread out flat,and over and beyond this edge and even on to the grasping plate 5. Ifdesired, it would also be possible to design the first grasping plate asa fork-shaped plate, so that not only the front, feed-side edge zone,but the entire grasping plate would be flush with the top side of thesupporting table 17.

As is apparent from a comparison of FIGS. 1, 3, and 6, the workpiecelayer W1 is transferred by means of the above-described feed conveyor Zby two superimposed pivoting movements. The workpiece W1 moves from thehorizontal top side of the supporting table 17 into a hanging position,in which the workpiece layer is made available to the scanning andaligning station R. During the pivoting movement of the arm 1 around theaxis A1, the workpiece layer W1 is brought from the horizontal into thevertical position, and at the same time pivoted by pivoting the gripper4 around the axis A2. The workpiece then is finally located in theextension of the arm, as is shown in FIG. 3.

It should be noted here that the feed conveyor Z' of the conveying meansF' is essentially identical to the above-described feed conveyor Z.Therefore, identical components are designated by the same referencenumerals, and the reference numerals for the feed conveyor Z' differfrom the reference numerals used for the feed conveyor Z only by a primesign ('). It should be noted in this connection that the same gear motor3 is used to pivot the arm 1' as to pivot the arm 1. This is achieved bythe gear motor 3 having a continuous shaft 2 and consequently twooutputs.

An intermediate plate 19, is fastened vertically in the frame G and isopposed on both sides by a clamp 20, 20' each at a predetermineddistance from and in the upper area of the intermediate plate 19. Theintermediate plate 19 is associated with the scanning and aligningstation R. By means of an aligning device 21 that is of a cross slidetype, at least one of the clamps 20 and 20', which are of identicaldesign is adjustable in two directions that are perpendicular to oneanother. These two directions are substantially in parallel to the planeof the intermediate plate 19. At least one of the clamps 20 and 20' isalso pivotable around an axis that is perpendicular to the intermediateplate. The aligning device 21 will be explained in greater detail inconnection with the clamp 20 on the basis of FIG. 7.

The aligning device 21 is accommodated within a housing 22 of thescanning and aligning station R. The housing is fastened to the frame G.A pin 23, which extends at right angles to the intermediate plate 19 andon which a support plate 24 is pivotably mounted, is fastened to thehousing 22. A stepping motor 25, which is hinged to the housing 22 andis connected, via a threaded spindle 26 and a threaded block 27, to abracket 28 which is a fixed component of the support plate 24. Thestepping motor 25 is used to perform the pivoting movement of thesupport plate 24.

A slide 30, which is displaceable essentially in the horizontaldirection, is accommodated in a guideway 29 of the support plate 24. Thedisplacement of the slide 30 in relation to the support plate 24 isbrought about by a stepping motor 32, which is fastened to a fixed stop31 of the support plate 24 and is connected to the slide 30 via athreaded spindle 33.

A second slide 35 that is displaceable essentially in the verticaldirection is accommodated in a guideway 34 of the slide 30. Thedisplacement of the slide 35 in relation to the first slide 30 isbrought about by a stepping motor 37, which is fastened to a fixed stop36 of the first slide 30 and is connected to the second slide 35 via athreaded spindle 38.

The clamp 20, which has a horizontally extending clamp bar 40 and aplurality of pneumatic cylinders 41 arranged on it, is fastened to aprojection 39 arranged at the lower end of the second slide 35. Thenumber of the pneumatic cylinders 41 and the distances between themcorrespond to the number of the respective openings 15 and 16 in therespective grasping plates 5 and 7, as well as to the distance betweenthe respective openings 15 and 16, respectively. The piston rods of thepneumatic cylinders 41, which are designated by 42, form clampingelements that will engage the workpiece layer W1. For engagement, thefree ends of the piston rods 42 are made conical. By admitting pressureinto the pneumatic cylinders 41, the workpiece layer W1 is pressed bythe piston rods 42 against the intermediate plate 19 acting as anabutment, and held in a form-locking manner as a result. In order forthe intermediate plate 19 not to be scratched by the movements of thetips of the piston rods 42, the pneumatic cylinders 41 are adjusted suchthat the tips of the piston rods 42 maintain a short distance from theintermediate plate 19 when pressure is admitted to the pneumaticcylinders 41.

It is thus possible to pivot the clamp 20 around a horizontal axis,which is determined by the pin 23, by means of the first stepping motor25. The second stepping motor 32 makes it possible to displace the clamp20 to and fro, and the third stepping motor 37 makes it possible toraise and lower the clamp 20.

An aligning device, which is designated by 21' is also associated withthe clamp 20' in this embodiment. The aligning device 21' is identicalto the above-described aligning device 21. Therefore, the same referencenumerals were used for identical components if they are represented inthe drawing, and the reference numerals for the aligning device 21' aredistinguished from the reference numerals for the aligning device 21 bya prime sign.

Since a separate aligning device 21 or 21' is associated with each clamp20 and 20', each of the two clamps 20 and 20' can consequently belinearly adjusted in two mutually perpendicular directions in relationto the respective other clamp 20' or 20, and also be pivoted in theplane defined by these two directions.

The scanning and aligning station R has one optical scanning device 43and 43', respectively, for each workpiece layer W1 and W2. The opticalscanning device 43 has three reflected light photocells 45, 46, and 47(FIGS. 3 and 4), which are arranged on a support 44 and cooperate withthe intermediate plate 19. The intermediate plate 19 is designed as areflecting plate in this area. The optical scanning device 43' has thesame design as the scanning device 43 and therefore also has threereflected light photocells 45', 46', and 47'.

The scanning devices 43, 43' are used for the point-by-point scanning ofthe workpiece layers W1 and W2 and consequently for detecting theirinstantaneous alignment position. The scanning devices 43 and 43' areconnected to a control device (not shown) that processes their signals.The control device is also connected to the stepping motors, 25 and 25',32 and 32', and 37 and 37' of the two aligning devices 21 and 21'. Thesestepping motors can be actuated and controlled, by the control device,as a function of the signals sent by the two scanning devices 43 and 43'in terms of mutual alignment of the contours of the workpiece layers W1and W2.

The transport mechanism or means T shown in FIG. 1 is formed by anendless conveyer belt 48, which extends in a horizontal plane beneaththe clamp 20, and runs around a drive wheel 49 and a deflecting wheel50. The transport mechanism T' located on the other side of theintermediate plate 19 is identical to the transport mechanism T, so thatthe components of the transport mechanism T' are designated by the samereference numerals as those of the transport mechanism T, and only aprime sign is added to them.

To drive the two conveyor belts 48 and 48', a common motor 51 isprovided, which is fastened to the frame G and is in drive connectionwith the shaft 52' of the drive wheel 49' shown in FIG. 2 A gear 53',which is in drive connection with a gear 53 fastened to the shaft 52 viaa reversing gear 54 formed by two gears, is fastened to the shaft 52'.The two conveyor belts 48 and 48' are thus driven in oppositedirections.

A deflecting wheel 56 mounted on a support 55 and, opposing this wheel,a deflecting wheel 58 mounted on a support 57, are arranged between tworuns 48a and 48b of the conveyor belt 48 at a site between the scanningand aligning station R and the drive wheel 49. The transport mechanism Tis subdivided by the deflecting wheels 56 and 58 into a first section T1extending from the deflecting wheel 50 to the deflecting wheels 56 and58 and a second section T2 extending from the deflecting wheels 56 and58 to the drive wheel 49.

A pneumatic cylinder 59, whose piston rod 60 is hinged to a rod-shapedsupport 61, on which the deflecting wheel 50 is rotatably mounted, ispivotably mounted on the frame G. The pneumatic cylinder 59 makes itpossible to pivot the first section T1 of the transport mechanism T backand forth between a carrying position adjacent to the intermediate plate19 for carrying the workpiece layer W1 and a non-carrying position thatis located farther away from the intermediate plate 19. The runs 48a and48b can be pivoted around an axis that coincides with the longitudinalaxis of the respective support 55 and 57. The first section T1' of thetransport mechanism T' can also be pivoted back and forth by means ofthe pneumatic cylinder 59' in the same manner.

In the non-carrying position of the sections T1 and T1', the runs 48aand 48a' are at a sufficiently great distance from the intermediateplate 19, so that the grippers 4 and 4' together with the workpiecelayers W1 and W2 can be pivoted unhindered into the area of the clamps20 and 20'.

The runs 48a and 48a' of the conveyor belts 48 and 48' may be supported,if desired, on the rear side in the area of the two sections T1 and T2as well as T1' and T2' in order to ensure the necessary holding effecton the workpiece layers to be transported. Such supporting, which can bebrought about by, e.g., rail-like supports provided with pressurerollers, is not shown in the drawings for clarity's sake.

The sewing station N contains a sewing machine 62 that is fastened to aslide 63. The slide 63 is mounted on a vertically extending guide rail64 and can be moved up and down by means of a chain drive 65. Foraccurate guiding of the workpiece layers to be sewn to one another, aguiding device 66 is arranged on the sewing machine 62. Such a guidingdevice is described in, e.g., West German Utility Patent No. DE-GM85,16,184, hereby incorporated by reference, so that it is unnecessaryto discuss it here in greater detail.

The device operates as follows:

Two workpiece layers W1 and W2 are placed on the supporting table 17with the grippers 4 and 4' being in the pickup position according toFIG. 5, and the front edge of the workpiece layers W1 and W2 is flushwith the discharge-side edge of the grasping plates 5 and 5'. Thegrasping plates 7 and 7' are subsequently pivoted downward toward thegrasping plates 5 and 5', and as a result of which the workpiece layersW1 and W2 are clamped in the grippers 4 and 4' according to FIG. 1.

After the grippers 4 and 4' have grasped the workpiece layers W1 and W2,the arms 1 and 1' are pivoted upward around the axis A1, and thegrippers 4 and 4' are pivoted around the axes A2 at the same time. Thearms are pivoted so that the grippers 4 and 4' and the workpiece layersW1 and W2 will assume the position shown in FIG. 3. In order for thegrippers 4 and 4' to be able to be moved unhindered into this position,the sections T1 and T1' of the transport mechanisms T and T' must be inthe non-carrying position, i.e. removed from the intermediate plate 19,and the piston rods 42 forming the clamp elements must be withdrawn.

As soon as the grippers 4 and 4' reach the position shown in FIG. 3,pressure is admitted into the pneumatic cylinders 41 of the clamps 20and 20' as a result of which their piston rods 42 will grasp theworkpiece layers W1 and W2 through the openings 15, 16, 15' and 16' andfix them in cooperation with the intermediate plate 19. The grippers 4and 4' are subsequently opened and pivoted into the pickup positionshown in FIG. 5 to transfer the next workpiece layers.

After the workpiece layers W1 and W2 have been taken over by the clamps20 and 20', the instantaneous position of the workpiece layers W1 and W2is determined by means of the scanning device 43 and 43'. The angularposition of the front, downwardly extending edge of the workpiece layersW1 and W2 is first measured by the reflected light photocells 46 and 47as well as 46' and 47', and angular adjustment of the workpiece layersW1 and W2 is performed by energizing the stepping motor 25 and/or 25' inthe case of deviations from the desired aligned position. The verticaland horizontal relative positions of the two workpiece layers W1 and W2are subsequently determined by means of the reflected light photocells45 and 47 as well as 45' and 47', and mutual alignment of the workpiecelayers W1 and W2 is performed by energizing the corresponding steppingmotors 32 and 37 as well as 32' and 37' in the case of a difference. Thevertical and horizontal alignments are performed by simultaneouslyactuating the corresponding stepping motors 32 and 32' as well as 37 and37' in opposite directions, as a result of which the time required foralignment is reduced to a minimum.

On completion of the mutual alignment of the workpiece layers W1 and W2,the sections T1 and T1' of the transport mechanisms T and T' are pivotedinto the carrying position, while the motor 51 is still turned off. Inthe carry position, the sections T and T' grasp the workpiece layers W1and W2 just below the clamps 20 and 20' in conjunction with theintermediate plate 19 acting as an abutment.

As soon as the transport mechanisms T and T' have grasped the workpiecelayers W1 and W2, the clamps 20 and 20' are opened by releasing thepressure from the pneumatic cylinders 41, and the motor 51 is thenturned on. After turning on the motors the workpiece layers W1 and W2are together moved in the direction of the sewing station N, while theirmutually aligned positions are maintained. The together workpiece layersW1 and W2 are then stopped in the sewing position by turning off themotor 51 after the sewing station has been reached.

As soon as the workpiece layers W1 and W2 have been transported beyondthe contact points of the deflecting wheels 56 and 58 of the transportmechanism T and the corresponding contact points of the deflectingwheels (not shown) of the transport mechanism T' and are in the area ofthe second sections T2 and T2', the first sections T1 and T1' are againpivoted into the non-carrying position. It is thus possible to introducethe next workpiece layers into the scanning and aligning station R evenat this point in time and to transfer the next workpiece layers to theclamps 20 and 20', so that time-overlapped, efficient operation ispossible.

In the sewing position, the edge zones of the two workpiece layers W1and W2, are to be sewn together, and the edge zones project slightlyover the vertical edge of the intermediate plate 19 according to FIG. 2.

To carry out the sewing process, the sewing machine 62 is moved downwardfrom the resting position shown in FIG. 1, and the projecting edge zonesof the workpiece layers W1 and W2 are grasped by the guiding device 66.As soon as the sewing machine 62 reaches the upper edge of the workpiecelayers W1 and W2, it is turned on After turning on, the sewing machine62 forms an edge-parallel connection seam along a front longitudinaledge of the workpiece layers W1 and W2 in cooperation with the guidingdevice 66. Since the workpiece layers are held only in the area of theirtop transverse edge and hang down freely otherwise, the guiding device66 being moved downward in the vertical direction along a straight pathtogether with the sewing machine 62 is able to guarantee, due tocorresponding transverse or pivoting movements of parts of the workpiecelayers W1 and W2, edge-parallel sewing even in edge zones in which thecourse of the edge deviates from the vertical.

Embodiment 2

The embodiment shown in FIG. 8 pertains to a device in which theworkpiece layers W3 and W4 are aligned hanging on a longitudinal side,rather than hanging on a narrow side, as in the case of theabove-described device according to the first embodiment.

The device according to FIG. 8 has essentially the same design as thedevice according to FIGS. 1 through 7, and therefore it also consists ofa frame GA, two conveying mechanisms FA and FA', a scanning and aligningstation RA, as well as a sewing station NA. The conveying means FA andFA' likewise comprise one feed conveyor ZA and ZA', respectively, forfeeding two workpiece layers W3 and W4 to the scanning and aligningstation RA, as well as one transport mechanism TA and TA' each,respectively, for forwarding the aligned workpiece layers W3 and W4 tothe sewing station NA.

The feed conveyors ZA and ZA' differ from the feed conveyors Z and Z' ofthe first embodiment solely by the greater length of the grippers 104and 104', and the greater length is due to the fact that the grippers104 and 104' grasp the workpiece layers W3 and W4 on a longitudinalside.

The aligning devices (not shown) of the scanning and aligning station RAare fully identical to the scanning and aligning station R according tothe first embodiment. Only the clamps 120' (the opposite clamp is notshown) have been made wider, corresponding to the length of thelongitudinal sides of the workpiece layers W3 and W4. The scanningdevices (not shown) also must be adjusted to the special alignedposition of the workpiece layers W3 and W4 in the same manner.

The transport mechanisms TA and TA' are also essentially identical tothe transport mechanisms T and T' of the first embodiment, and aretherefore also subdivided into first sections TA1 and TA1', which can bemoved back and forth between a carrying position and a non-carryingposition, and second sections TA2 and TA2'.

Only the sewing station NA does differ more substantially from thesewing station N, because the sewing machine 162 is provided with aguiding device 166 that is not movable, but is arranged stationarily onthe frame GA Moreover it is also in a differently aligned position.

The modes of operation of the conveying means FA and FA' and of thescanning and aligning station RA are the same as those of thecorresponding basic components of the first embodiment, so that it isunnecessary to discuss them in greater detail here.

There is a difference only in the manner in which the sewing process iscarried out. Contrary to the first embodiment, the relative movementbetween the sewing machine 162 and the workpiece layers W2 and W4, whichis necessary for seam formation, takes place here as a result of thefact that the transport mechanisms TA and TA' pulls the alignedworkpiece layers W3 and W4 out of the scanning and aligning station in acontinuous movement process. W3 and W4 are then moved together along thestationary sewing machine 62. This forms, in cooperation with theguiding device 166, an edge-parallel connection seam along the upperlongitudinal edge. Since the seam is formed at a short distance from thetransport mechanisms TA and TA' holding the workpiece layers W3 and W4,and the narrow strip of workpiece projecting over the transportmechanism TA and TA' is relatively inflexible, workpiece layers withstraight or only slightly contoured edges can advantageously beprocessed with the device according to the second embodiment. Forprocessing workpiece layers with highly contoured edges, it could beadvantageous to arrange the sewing machine at right angles to thedirection of feed and to control its distance from the course of theedge by the signals of an edge scanning device.

The transport mechanisms TA and TA' not only remove the workpiece layersW3 and W4 from the scanning and aligning station RA, but also performthe feed movement necessary for seam formation at the same time. Thetransport mechanisms TA and TA' are therefore not stopped during thesewing process, unlike in the first embodiment, and the next workpiecelayers can be aligned in conjunction with the process according to whichthe first sections TA1 and TA1' are pivoted into a non-carrying positionduring sewing, in the scanning and aligning station already during thistime. It is thus possible to work with a relatively rapid succession ofworkpiece layers with a time overlap.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the application of the principles ofthe invention, it will be understood that the invention may be embodiedotherwise without departing from such principles.

What is claimed is:
 1. A process for bringing together and co-processingsubstantially horizontal first and second workpieces, the processcomprising the steps of:moving the first and second workpieces from ahorizontal starting position to a vertical orientation at a scanning andaligning station by a conveying means; said scanning and aligningstation grasping the first and second workpieces from said conveyingmeans; scanning and aligning the first and second workpieces with eachother at said scanning and aligning station; providing a transport meansfor transporting said aligned first and second workpieces to aprocessing site, said transport means having a first section and asecond section; moving said first section to a non-carrying positionwhen said conveying means is moving the first and second workpieces tosaid scanning and aligning station, and when said scanning and aligningstation is scanning and aligning the first and second workpieces, inorder to allow operation of said conveying means and said scanning andaligning station; moving said first section to a carrying position aftersaid scanning and aligning, to cause said first section to grasp thealigned first and second workpieces for said transporting to saidprocessing site.
 2. A process in accordance with claim 1, wherein:saidscanning and aligning is performed on an edge of the first and secondworkpieces; said transferring of said aligned first and secondworkpieces by said transport means is along a direction substantiallyperpendicular to said aligned edge of said first and second workpieces;and stopping said first and second workpieces at said processing site;and connecting said stopped first and second workpieces with a stitchforming machine at said processing site.
 3. A process in accordance withclaim 1, wherein:said scanning and aligning is performed on an edge ofthe first and second workpieces; said transferring of said first andsecond workpieces by said transport means is along a directionsubstantially parallel to said aligned edge of said first and secondworkpieces; and transporting said aligned first and second workpiecesthrough said processing site; and connecting said transported first andsecond workpieces with a stitch forming machine during said transportingof said aligned first and second workpieces through said processingsite.
 4. A process in accordance with claim 1, furthercomprising:positioning said grasped first and second workpiecessubstantially flat opposite each other during said moving to saidscanning and aligning station.
 5. A process in accordance with claim 2,wherein:said stitch forming machine performs said connecting on saidedge of said stopped first and second workpieces.
 6. A process inaccordance with claim 3, wherein:said stitch forming machine performssaid connecting on said edge of said first and second workpieces duringsaid transporting of said first and second workpieces through saidprocessing site.
 7. A process in accordance with claim 5, furthercomprising:moving said stitch forming machine along said edge of saidstopped first and second workpieces.
 8. A process for bringing togetherand co-processing substantially horizontal first and second workpieces,the process comprising the steps of:providing a substantially horizontalsupport table; providing first and second arms pivotal at one end, eachof said arms having a gripper at another end of said arms, said grippershaving first and second plates; positioning said first plate of saidgrippers substantially flush with a surface of said support table;positioning the first and second workpieces in between said first andsecond plates of said grippers of said first and second armsrespectively; clamping the first and second workpieces in said grippersof said first and second arms respectively; pivoting said first andsecond arms about said pivotal ends to move the clamped first and secondworkpieces to a scanning and aligning station; pivoting said grippersduring said pivoting of said arms to position the first and secondworkpieces substantially parallel to each other; turning the first andsecond workpieces into a substantially vertical position during saidmoving; scanning and aligning the first and second workpieces with eachother at said scanning and aligning station; transferring said alignedfirst and second workpieces to a processing site.
 9. A process inaccordance with claim 8, wherein:said support table is provides withgrooves, and said first plate of said grippers is positioned in saidgrooves for said flush positioning of said first plate with said surfaceof said support table.